Original Paper Received: August 5, 2013 Accepted: November 26, 2013 Published online: July 29, 2014
Caries Res 2014;48:566–574 DOI: 10.1159/000357596
A Comparative Study of Different Radiographic Methods for Detecting Occlusal Caries Lesions Elif Tarım Ertas a Ebru Küçükyılmaz b Hüseyin Ertaş c Selçuk Savaş b Meral Yırcalı Atıcı a
Departments of a Oral and Maxillofacial Radiology, b Pedodontics and c Endodontics, Faculty of Dentistry, Izmir Katip Çelebi University, Izmir, Turkey
Key Words Computed tomography · Dental caries · Diagnosis · Digital · Radiography
Abstract Objectives: The aim of this in vitro study was to compare the diagnostic accuracy of different radiographic imaging modalities in detecting occlusal caries lesions. Materials and Methods: Under standardized conditions, 125 extracted human permanent molar teeth with sound or occlusal caries lesions were radiographed using a conventional film system (F-speed), a direct digital imaging system (complementary metal oxide semiconductor sensor), an indirect digital imaging system (photostimulable phosphor plate) and a cone beam computed tomography system (CBCT). Two observers scored the resultant images for the presence or absence of caries. Then, the teeth were histologically prepared and a definite diagnosis was determined by stereomicroscopic assessment. The area under the receiver operating characteristic curve (Az), sensitivity, specificity and accuracy of each imaging modality were calculated, as well as the intra- and interexaminer reproducibility. Results: For both thresholds, interexaminer agreement were higher for CBCT. For intraexaminer agreement, observers had different scores for both thresholds, but the scores were generally higher for CBCT. Similar Az values were achieved with all imaging methods at
© 2014 S. Karger AG, Basel 0008–6568/14/0486–0566$39.50/0 E-Mail [email protected] www.karger.com/cre
a diagnostic D1 threshold. The Az values of the CBCT system were found to be statistically higher than those of the other imaging modalities at a diagnostic D3 threshold (p > 0.05); no significant differences were found among the other imaging modalities. All radiographic methods showed similar sensitivities, specificities and accuracy in detecting D1 threshold. The CBCT system showed higher sensitivity and accuracy in detecting dentine lesions. Conclusions: Within the limitations of this study, CBCT exhibited better performance in detecting deep occlusal caries lesions than the other radiographic systems. © 2014 S. Karger AG, Basel
In recent years, the prevalence of dental caries has declined worldwide in a remarkable way [Rathore et al., 2012]. However, accurately diagnosing occlusal pit and fissure caries and detecting incipient lesions are important issues for clinicians [Souza-Zaroni et al., 2006]. Using a visual/tactile method when diagnosing occlusal caries is the oldest and most common method preferred by dentists in clinical practice [Rathore et al., 2012]. Since occlusal caries can progress without visible breakdown of the enamel structure [Poorterman et al., 2000], visual examination alone is not always sufficient for diagnosing occlusal caries. In the literature, although visual inspection has been reported to be highly specific [Heinrich-Weltzien et Elif Tarım Ertaş, DDS, PhD Department of Oral and Maxillofacial Radiology Faculty of Dentistry, Izmir Katip Çelebi University TR–35180 Izmir (Turkey) E-Mail dteliftarim @ yahoo.com
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Different Radiographic Methods for Detecting Caries
[Kamburoğlu et al., 2011], at a lower cost and with lower absorbed doses than with the conventional computed tomography used in medical radiology [Tyndall and Rathore, 2008], a new technology that uses a 2D sensor and a cone-shaped beam in place of the fan-shaped X-ray beam used for conventional computed tomography has been developed [Haiter-Neto et al., 2008]. The development of cone beam computed tomography (CBCT) has been revolutionary in that this technology [Rathore et al., 2012] offers a number of potential advantages over conventional tomography, including easier image acquisition, higher image accuracy, fewer artifacts, lower effective radiation doses (up to 15 times lower than those of conventional computed tomography scans), faster scan times and greater cost effectiveness [Scarfe and Farman, 2008; Tyndall and Rathore, 2008]. This technique could be applied in several dental diagnostic areas, such as implant treatment, craniofacial anomalies, endodontic treatment, orthodontics, periodontology [Arai et al., 1999; Ziegler et al., 2002; Danforth, 2003] and caries diagnosis [Kayipmaz et al., 2011]. In the literature, the results of studies using CBCT for caries detection are not consistent with each other. In some studies, promising results have been reported in the detection of caries lesions [Haiter-Neto et al., 2008], while in another study, a limited CBCT system was found to be superior to conventional film and storage phosphor radiography for the in vitro assessment of approximate caries lesion depth [Akdeniz et al., 2006]. Tsuchida et al. [2007] and Haiter-Neto et al. [2008] had raters score images of teeth made with a CBCT unit and found no benefit over film for detecting incipient proximal surface caries [Young et al., 2009]. Thus, there are no clear conclusions regarding the value of CBCT for detecting caries in the literature. The purpose of the present study was to compare the caries diagnostic accuracy of conventional film radiography (Fspeed film), a direct digital imaging system (CMOS sensor), an indirect digital imaging system (PSP plate) and a CBCT unit that provides high-resolution images with the smallest voxel size (0.075 mm) on the market for the in vitro determination of occlusal caries.
Materials and Methods This study was approved by the Research Ethics Committee of Izmir Katip Çelebi University (registration number 2013-39). Sample Selection A total of 125 extracted permanent molar teeth exhibiting complete root formation were included in this study. Altered physical properties in the tooth structure, large cavitated surfaces and den-
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al., 2005; Reis et al., 2006], these methods are subjective, which normally leads to low sensitivity and reliability results [Ketley and Holt, 1993; Costa et al., 2002]. In order to overcome difficulties during diagnosis and enable better detection of occlusal caries, radiographic examinations, especially conventional film and digital intraoral radiography, are the most easily accessible techniques for improving caries detection in routine clinical practice [Kamburoğlu et al., 2010, 2011]. Recent developments in imaging systems and the production of new sensor types and advanced software programs offer increasing clinical advantages [Kayipmaz et al., 2011]. Although the image resolution of conventional film is superior to that of digital images [Parks and Williamson, 2002], this technique requires more radiation to produce an image of diagnostic quality; therefore, many professionals are now replacing conventional film radiographs with digital radiography, due to its many advantages [Cederberg et al., 1998; Paurazas et al., 2000; Williams, 2001; Kitagawa et al., 2003; Naoum et al., 2003; Kayipmaz et al., 2011]. There are several digital radiographic systems currently used in dental practice as an alternative to film-based radiography [Pontual et al., 2010]. The most common direct digital imaging systems use solid state sensors – either a charge-coupled device (CCD) or a complementary metal oxide semiconductor (CMOS); indirect digital imaging systems use photostimulable phosphor (PSP) plates, also known as storage phosphor plates [Kamburoğlu et al., 2010]. Although digital systems have a number of advantages [Wenzel, 1995; Hintze et al., 2002; Jacobsen et al., 2004], such as lower exposure dose, reduced working time from image exposure to image display (no wet processing is involved), lack of destroyed processing artifacts often experienced with conventional film, and possible image quality enhancements, such as contrast and density modulation, which might increase diagnostic accuracy [Wenzel, 1995, 2000; Hintze et al., 2002; Pai and Zimmerman, 2002], all of these systems are able to provide two-dimensional (2D) information about dental tissues and diseases [Wenzel, 2000]. Another disadvantage of 2D radiographs is that the apparent depth can also vary as a function of X-ray beam angulation [van der Stelt et al., 1989; Chadwick et al., 1999] and radiographic density [Versteeg et al., 1997], which can lead to variations in perception. The perceived lesion depth can lead dentists to erroneously believe that caries has progressed or regressed, resulting in unnecessary restorative intervention or delay in treatment [Akdeniz and Gröndahl, 2005]. Due to the high demand for a technique that can provide three-dimensional (3D) data at the tooth level
Conventional Film Radiography A bitewing technique using size 2 (3 × 4 mm) F-speed film (CFSPEEDX, Medex Medical Imaging, Nice, France) and standardized bitewing projection geometry was used. The intraoral X-ray unit (eXTtend; MyRay, Imola, Italy) was operated at 65 kV, 7 mA with 2.5 mm aluminium equivalent filtration. Focus-to-film distance was 30 cm. Each tooth was mounted in a block of silicone paste to ensure a reproducible geometry. While the vinyl polysiloxane putty was still soft, the film holder was pressed into it, and once hardened, the putty allowed quick realignment of the specimen as well as CMOS sensor, PSP plate and F-speed conventional films. A 20-mm-thick soft tissue equivalent Plexiglas block was placed close to the tooth and facing the X-ray tube to simulate scatter radiation and beam attenuation from soft tissues. The F-speed films were exposed for 0.25 s to generate an optimal density subjectively for caries detection [Sogur et al., 2011]. The exposed films were automatically processed (Velopex Extra-X; Medivance Instruments Ltd., London, UK) using fresh Kodak developer and fixer solutions. Direct Digital Radiography – CMOS Sensor Standardized images of the teeth were obtained using the same intraoral X-ray unit, but with a size 1 (37 × 24 mm) CMOS sensor (DIGORA Toto; SOREDEX, Milwaukee, Wisc., USA) with the same standardized projection geometry. The CMOS sensors were exposed for 0.12 s to generate an optimal density subjectively for caries detection [Sogur et al., 2011]. The direct digital imaging system provides three types of diagnostic modes (dentoenamel, periodontal and endodontic) at two levels (high and low) of spatial resolution. In this study, the exposures with the CMOS sensor were performed in the dentoenamel high-resolution mode, which was recommended by the manufacturer to provide high-contrast images for caries detection.
at a fixed 110 kVp setting, automated adjusted milliamperes and a scan time of 36 s. The volumetric data from the CBCT system were reconstructed and sectioned into 0.075-mm pieces in the mesiodistal tooth plane. Evaluation of Radiographic Methods The images were organized into groups of images from a particular exposure setting and system. Two observers (one pedodontist and one oral and maxillofacial radiologist) independently viewed the image groups in random order. The oral and maxillofacial radiologist with 10 years of experience in image interpretation provided a training session to familiarize the other observer with the presentation of all imaging methods and was given brief information about the use of the NNT viewing software (version 3.10, QR srl, Verona, Italy) on how to observe the CBCT images. Then the observers discussed and scored a number of teeth with carious lesions with different radiographic methods for calibration. The digital and CBCT images were displayed using the dedicated software of each imaging system incorporated into the same computer. Observation conditions were optimized by using the same computer monitor to display the images; the display ratio was 1:1. Viewing distance was kept constant, at about 50 cm, for all observers, and the lights were dimmed during the observations. The observers were not given the option of performing any image enhancements to avoid the production of a variety of different digital images. Conventional film radiographs were examined on a light box and at 2× magnification. A period of at least 1 day separated each viewing session. All tooth surfaces were examined for the presence of carious lesions on the occlusal surfaces, using a five-point confidence rating scale: 0 = no caries; 1 = radiolucency extending to the outer half of the enamel; 2 = radiolucency extending to the inner half of the enamel; 3 = radiolucency extending to the outer half of the dentine; 4 = radiolucency extending to the inner half of the dentine. Intraobserver agreement was assessed by having each observer view all images twice, with a 2-week interval between viewing to eliminate memory bias.
Indirect Digital Radiography – PSP Plate System Standardized images of the teeth were obtained using the same intraoral X-ray unit, but with size 2 (31 × 41 mm) VistaScan blue storage phosphor plates (Dürr Dental, Bietigheim-Bissingen, Germany) with the same standardized projection geometry. The PSP plates were exposed for 0.12 s to generate an optimal density subjectively for caries detection [Sogur et al., 2011]. The plates were later scanned in a VistaScan scanner. The PSP plates were stored in lightproof envelopes during the exposure and scanned immediately after exposure using the VistaScan scanner. The highresolution scan mode was selected from the scanner setup menu, as recommended by the manufacturer for most diagnostic tasks.
Histological Validation The teeth were individually embedded in acrylic (Vipcril; Vipi, São Paulo, Brazil) and serially sectioned into 700-μm-thick sections in the mesiodistal direction, using a water-cooled 200-μm diamond band. The histological examination was performed by one of the study authors (E.K.), with experience from several previous in vitro studies, using a stereomicroscope with a magnification of 10–20× under reflected light (Olympus SZ61, Tokyo, Japan). Caries was defined as being present when demineralization was observed, seen as a white or discolored (yellow/brown) area. The histological criteria for caries lesion depth were: 0 = no caries; 1 = demineralization extending to the outer half of the enamel; 2 = demineralization extending to the inner half of the enamel; 3 = demineralization extending to the outer half of the dentine; 4 = demineralization extending to the inner half of the dentine. As a measure of histological assessment reliability, all of the sections were re-examined after 10 days. Almost perfect agreement was reached between the first and second histological examinations.
CBCT Each tooth block was also radiographed using a NewTom 5G CBCT system (Verona, Italy) with a 6 × 6 cm field of view in the high-resolution denture scan mode. The voxel size was 0.075 mm3
Statistical Analysis The analyses of the caries detected on the radiographs were performed at two different thresholds: enamel and dentine caries lesions (D1 threshold; sound vs. decayed) and dentine caries le-
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tal restorations were not included in the study sample. The occlusal surfaces ranged from sound to varying degrees of fissure, discoloration and possible microscopic breakdown of the surface structure; however, none of the teeth showed macroscopic signs of cavity formation with exposure into the dentine. The teeth were stored in 0.1% thymol solution for less than 3 months from the time of extraction. For the study, the teeth were radiographed using four different radiographic methods.
Color version available online
1.0
0.6
Results 0.4 Source of the curve Conventional film PSP CMOS CBCT Reference line
0.2
0 0
0.2
0.4 0.6 1 – Specificity
0.8
1.0
Fig. 1. Area under the ROC curve values of all radiographic detec-
tion methods at the D1 threshold. Diagonal segments are produced by ties.
Table 1. Sensitivity, specificity, accuracy and Az scores of all radio-
graphic detection methods at the D1 threshold Test method
Az
Sensitivity Specificity Accuracy
Conventional film PSP CMOS CBCT
0.851 0.824 0.834 0.801
0.798 0.713 0.830 0.926
0.903 0.935 0.839 0.677
0.824 0.768 0.832 0.864
sions (D3 threshold), based on the histological evaluation as the gold standard. The appropriate cutoff point for the D1 threshold was a score of 1 or above, considering the gold standard scores 1, 2 and 3 as evidence of disease for all radiographic methods. The appropriate cutoff point for the D3 threshold was a score of 3 or above, considering the gold standard scores 3 and above as evidence of disease for all radiographic methods. Data were presented and analyzed separately for each examiner. Inter- and intraexaminer reliabilities were calculated using Cohen’s kappa test after collapsing the results into two categories: D1 and D3 thresholds. For each observer and each radiographic modality, the sensitivity (cumulative percentage of carious enamel lesions identified among those that had carious lesions), specificity (cumulative percentage of sound surfaces identified among those who had sound surfaces) and accuracy (percentage of correct scores) were computed. To compare the performance of methods
Different Radiographic Methods for Detecting Caries
Distribution of Lesions A total of 125 occlusal surfaces were examined in the study. According to the histological examination, the status of the 125 occlusal surfaces was: 31 (24.8%) sound, 11 (8.8%) with caries lesions extending into the outer half of the enamel, 47 (37.6%) with caries lesions extending into the inner half of the enamel, 29 (23.2%) with caries lesions extending into the outer half of the dentine, and 7 (5.6%) with caries lesions extending into the inner half of the dentine. Occlusal Lesions at the D1 Threshold The sensitivity scores of the CBCT images of occlusal lesions at the D1 threshold were higher than those of the other imaging methods, while the specificity scores were lowest. However, the diagnostic accuracy of all radiographic systems was assessed using the Az, and similar accuracy scores were obtained with all imaging methods at the D1 threshold. A comparison of the Az values showed that the differences between the radiographic methods were not significant (p = 0.401 between conventional film and PSP plate, p = 0.725 between conventional film and CMOS sensor, p = 0.338 between conventional film and CBCT, p = 0.840 between PSP plate and CMOS sensor, p = 0.663 between PSP plate and CBCT, p = 0.447 between CMOS sensor and CBCT) (fig. 1). Table 1 shows the sensitivity, specificity, accuracy and Az values of all radiographic methods at the D1 threshold. Occlusal Lesions at the D3 Threshold The sensitivity scores of the CBCT images of occlusal lesions at the D3 threshold were higher than those of the other imaging methods. At the D3 threshold, similar specificity and accuracy scores were obtained with all imaging methods. A comparison of the Az values showed significant differences between CBCT and the other radiographic methods (p = 0.029 between conventional film and CBCT, p = 0.023 between PSP plate and CBCT, p = 0.014 between CMOS sensor and CBCT). There were Caries Res 2014;48:566–574 DOI: 10.1159/000357596
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Sensitivity
0.8
among each other, receiver operating characteristic (ROC) analyses were performed, and the area under the ROC curve (Az) at the D1 and D3 thresholds was calculated. Comparison of ROC curves was calculated with the statistics program MedCalc 9.3.0.0 (Mariakerke, Belgium). The analyses were performed using the SPSS statistics program for Windows, version 11.5 (SPSS Inc., Chicago, Ill., USA). For all statistical analyses, the level of significance was p < 0.05.
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1.0
0.6
Az
Sensitivity Specificity Accuracy
Conventional film PSP CMOS CBCT
0.739a 0.730a 0.717a 0.875b
0.500 0.472 0.444 0.806
0.978 0.989 0.989 0.944
0.840 0.840 0.832 0.904
Different superscript letters show a significant difference between methods.
0.4 Source of the curve Conventional film PSP CMOS CBCT Reference line
0.2
0 0
0.2
0.4 0.6 1 – Specificity
0.8
1.0
Fig. 2. Area under the ROC curve values of all radiographic detec-
tion methods at the D3 threshold. Diagonal segments are produced by ties.
no differences among the other methods at the D3 threshold (p = 0.899 between conventional film and PSP plate, p = 0.732 between conventional film and CMOS sensor, p = 0.560 between PSP plate and CMOS sensor) (fig. 2). Table 2 shows the sensitivity, specificity, accuracy and Az values of all radiographic methods at the D3 threshold. In the kappa analysis of interexaminer agreement between the observers, conventional film radiography had the lowest scores at the D1 threshold, while the CBCT images had higher scores at both the D1 and D3 thresholds compared with the other methods. At the D3 threshold, repeatability between the observers was similar for all imaging methods and higher than the scores obtained at the D1 threshold (table 3). There was a high level of intraexaminer agreement between the two assessments of the observers for the CBCT images at the D3 threshold. The overall intraexaminer scores were compatible between the observers at both thresholds. Table 4 shows the intraexaminer agreement scores of both observers at both thresholds.
Discussion
The present research focused mainly on the diagnostic accuracy and reliability of observers regarding images obtained using different X-ray systems. This study found 570
Test method
Caries Res 2014;48:566–574 DOI: 10.1159/000357596
Table 3. Interexaminer kappa scores (with standard errors) of all radiographic detection methods at the D1 and D3 thresholds
Test method
D1
D3
Conventional film PSP CMOS CBCT
0.473 (0.071) 0.654 (0.068) 0.518 (0.083) 0.833 (0.061)
0.822 (0.070) 0.804 (0.071) 0.763 (0.079) 0.980 (0.020)
that intraoral analogue X-ray film, direct and indirect digital X-ray modalities (CMOS sensor and PSP plate) and CBCT performed similarly in detecting occlusal caries at the D1 threshold, and that CBCT performed better at the D3 threshold. In the present study, the occlusal surfaces ranged from sound to varying degrees of fissure, discoloration and possible microscopic breakdown of the surface structure; however, none of the teeth showed macroscopic signs of cavity formation with exposure into dentine, as we believe that if diagnostic differences between radiographic systems are to be found, their accuracy in detecting subtle pathological changes should be tested. An in vitro model was preferred in this radiological study, as ideal patient positioning is not always possible in an in vivo study and absolute reproducibility is limited. In addition, image quality may vary from one patient to another. Another advantage of this in vitro model is that the occlusal surfaces can be exposed to X-rays repeatedly and ideal positioning of the specimen with exact reproducibility is possible. However, the results of the present study might not correlate with clinical situations. This is because in clinical settings, movement of the patient decreases image resolution, restorations in the occlusal plane can cause metallic streaking artifacts in the occlusal plane, and the other head and neck structures can result Tarım Ertas/Küçükyılmaz/Ertaş/Savaş/ Yırcalı Atıcı
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Sensitivity
0.8
Table 2. Sensitivity, specificity, accuracy and Az scores of all radiographic detection methods at the D3 threshold
Table 4. Intraexaminer kappa scores (with standard errors) of all radiographic detection methods at the D1 and
D3 thresholds
Conventional film PSP CMOS CBCT
D1
D3
examiner 1
examiner 2
examiner 1
examiner 2
0.872 (0.044) 0.824 (0.051) 0.513 (0.077) 0.776 (0.067)
0.610 (0.073) 0.727 (0.059) 0.714 (0.064) 0.935 (0.037)
0.546 (0.111) 0.548 (0.106) 0.666 (0.093) 0.918 (0.040)
0.647 (0.100) 0.834 (0.072) 0.965 (0.035) 0.938 (0.035)
in scattering into the field of interest, thereby reducing contrast [Ricketts et al., 1995]. The accuracy of 2D systems is well established in the literature [Rathore et al., 2012]; however, the accuracy of both intraoral analogue X-ray film and digital X-ray sensor measurements is limited by the 2D nature of the technology. The lower radiation doses, superimposition of anatomical structures and patient-related factors that affect caries diagnosis are inevitable factors with 2D systems [Kamburoğlu et al., 2011]. In addition, the differences in mass between small, incipient lesions and the surrounding tissues are so small that they do not reflect density differences with 2D images [Akdeniz and Gröndahl, 2005]. In the past decade, the use of CBCT in dentistry has become more and more widespread, as the CBCT technology overcomes the irradiation geometry problems that can cause errors in caries diagnosis with 2D imaging [Akdeniz and Gröndahl, 2005]. In this study, the observers were calibrated for each radiographic interpretation, but some differences between the observers still occurred, which may be due to their levels of experience and training with these radiographic methods. In the present study, ROC analysis was used to evaluate the diagnostic performance of four radiographic methods. In this analysis, significant differences among the areas under the ROC curves of the competing techniques were compared [Kantor et al., 1989], and it was found that the area under the curve (AUC) reflected diagnostic performance more comprehensively than sensitivity and specificity did, which are considered only one cutoff point [Kositbowornchai et al., 2004]. The ROC curve distinguishes between the inherent capacities of the observers to under- and overread when interpreting imaging; therefore, this analysis provides the most meaningful approach to comparing the diagnostic performance of two or more different imaging modalities [Rathore et al., 2012]. In this analysis, an area of 1 represents
a perfect test, and anything near 0.5 is a poor test result [Hintze et al., 2003]. In the present study, the AUC values of the four radiographic methods were around 0.80–0.85 at the D1 threshold, indicating that none of the methods was superior to the others and that they performed well at the D1 threshold. In addition, the CBCT AUC values were higher than those of the other methods at the D3 threshold, and the scores were close to those of the other methods. In recent years, several studies have been carried out to evaluate the accuracy of CBCT in detecting caries lesions on proximal and occlusal surfaces, with varying results [Haiter-Neto et al., 2008; Young et al., 2009; Kamburoğlu et al., 2010; Qu et al., 2011]. In 2007, Kalathingal et al. published a study comparing a CBCT device (SIDEXIS sensor; Sirona Dental Systems, Bensheim, Germany) and conventional film radiography in the detection of proximal caries, and their results showed no differences between the two methods. In the same year, Tsuchida et al. reported that the accuracy of the 3D Accuitomo in evaluating incipient proximal caries was not superior to that of intraoral films. Similar to their previous finding, Haiter-Neto et al. [2008] reported no differences in specificity or overall true scores among the methods when comparing the diagnostic accuracy of two CBCT systems – NewTom 3G (Verona, Italy) and 3DX Accuitomo – with one digital PSP (DIGORA fmx) and one conventional film system (Kodak Insight) in detecting occlusal caries. Contrary to previous findings, Young et al. [2009] reported that Accuitomo 3DX images were superior to CCD projection images in detecting lesions extending into the dentine on occlusal and proximal surfaces. However, the authors concluded that the 3DX images did not offer significantly superior information for detecting proximal surface caries limited to the enamel compared with CCD projection imaging. The possible explanation for these differences in study results is that both Tsuchida
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[2008], who reported that the sensitivity of the two CBCT systems (Accuitomo and NewTom) was high, but that their specificity was low, resulting in an increase in falsepositive results. Similarly, in their study, Young et al. [2009] found more false-positive results in intact teeth, thus resulting in significantly lower average specificity scores for the 3DX images than for the CCD images. A possible explanation for this might be the beam-hardening artifacts that appear in the pericoronal area and may mislead observers in distinguishing pathologies with low density, such as caries lesions [Tsuchida et al., 2007]. In addition, sound dentine under some cusps may appear artifactually more radiolucent than the surrounding dentine on the CBCT images, and this difference between enamel and dentine density might lead observers to misinterpret these areas as dentinal occlusal caries, thereby elevating the sensitivity scores while depressing the specificity scores [Young et al., 2009; Kayipmaz et al., 2011]. It is possible that better training of observers regarding this misinterpretation might improve the observers’ specificity scores without significantly depressing their sensitivity scores [Young et al., 2009]. In clinical practice, when referring a patient for CBCT examination, one of the most important issues to keep in mind is the effective radiation dose. Although the effective dose is somewhat lower than that of medical computed tomography, the dose is relatively higher than in conventional imaging alternatives and intraoral examinations. It is critical that the potential patient benefits from a radiographic examination be balanced against the risk of exposure to ionizing radiation [Ludlow et al., 2003], and it is fundamental that diagnostic radiology and CBCT procedures should be reserved for selected cases [Farman, 2005]. It should also be noted that CBCT is not considered suitable for routine caries diagnosis, because the large majority of patients have metallic restorations that cause artifacts due to beam hardening and scatter that simulates recurrent caries, and because the quality of CBCT images can be seriously affected by patient motion [Clifton et al., 1998]. In conclusion, the NewTom 5G CBCT exhibited higher sensitivity for detecting occlusal lesions than the intraoral systems did, but the overall accuracy scores were similar at the D1 threshold. CBCT was more accurate in detecting lesions at the D3 threshold than the intraoral systems. However, it can be concluded that because of the possible disadvantages of CBCT systems in clinical practice, including relatively higher effective radiation doses as well as possible misdiagnosis due to the artifacts caused by movement and metallic artifacts, intraoral radiograTarım Ertas/Küçükyılmaz/Ertaş/Savaş/ Yırcalı Atıcı
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et al. [2007] and Haiter-Neto et al. [2008] used a population of teeth in which the vast majority of the proximal surface lesions were limited to the enamel, whereas Young et al. [2009] evaluated both enamel and dentinal lesions equally. The different distribution of lesion depths would make detecting lesions more challenging, especially when they are located in enamel. In a recent study by Rathore et al. [2012], no statistically significant differences were reported between the Sirona Galileos (Sirona Dental Systems) CBCT and conventional film radiography in detecting occlusal caries. The results of the present study are consistent with the data in the literature in that there were no differences between the four imaging methods in detecting occlusal caries at the D1 threshold (sound/decayed), whereas CBCT was superior in detecting dentine lesions. CBCT systems offer a feature whereby an area can be evaluated in three planes at the same time (axial, sagittal and coronal), and sections can be created with different slice thicknesses and intervals. In the present study, we chose the mesiodistal plane to validate occlusal surfaces, as in this section, occlusal surface demineralization can be evaluated clearly [Haiter-Neto et al., 2008]. However, it is critical that if the operator fails to choose the slice that shows the deepest extension of the lesion, he/she may misdiagnose the lesions [Akdeniz and Gröndahl, 2005]. It has been suggested that the small voxel sizes and thin slices are the potential advantages of a CBCT system in caries diagnosis [Kayipmaz et al., 2011]. The CBCT device used in the present study (NewTom 5G) offers the smallest voxel size (0.075 mm3) available on the market, and this is the first study in the literature to evaluate accuracy at the smallest voxel size. However, no statistically significant differences were found among the four radiographic methods in the diagnosis of occlusal caries lesions at the D1 threshold, even with the smallest voxel size. Consistent with this finding, in a recent study, Kamburoğlu et al. [2010] compared intraoral digital CCD sensor images and CBCT images obtained at different voxel resolutions in the in vitro detection of occlusal caries, and the authors concluded that there were no statistically significant differences between ultra-resolution images and high- and low-resolution images. In the present study, although the CBCT images had the highest sensitivity scores, the CBCT specificity scores were lowest at the D1 threshold, which means that CBCT performs better when detecting true carious lesions, but weakly when detecting real sound surfaces. The present finding is consistent with the result of Haiter-Neto et al.
phy methods are found to be sufficient and have practical, economical and low-dose features that are valuable for the routine assessment of caries.
the manuscript: E. Tarım Ertas. Critical revision of the manuscript for important intellectual content: H. Ertaş, E. Tarım Ertas. Approval of the version of the manuscript to be published: E. Tarım Ertas, H. Ertaş, E. Küçükyılmaz, S. Savaş, M. Yırcalı Atıcı.
Author Contributions Conception and design of study: E. Tarım Ertas. Acquisition of data: S. Savaş, M. Yırcalı Atıcı. Analysis and/or interpretation of data: E. Tarım Ertas, E. Küçükyılmaz, H. Ertaş. Drafting of
Disclosure Statement The authors declare that they have no conflicts of interest.
Akdeniz BG, Gröndahl HG: Proximal caries depth: agreement between limited cone-beam CT, storage phosphore and film radiography. Hacettepe Dishekimligi Fakultesi Dergisi 2005;29:7–12. Akdeniz BG, Gröndahl HG, Magnusson B: Accuracy of proximal caries depth measurements: comparison between limited cone beam computed tomography, storage phosphor and film radiography. Caries Res 2006; 40: 202– 207. Arai Y, Tammisalo E, Iwai K, Hashimoto K, Shinoda K: Development of a compact computed tomographic apparatus for dental use. Dentomaxillofac Radiol 1999;28:245–248. Cederberg RA, Tidwell E, Frederiksen NL, Benson BW: Endodontic working length assessment. Comparison of storage phosphor digital imaging and radiographic film. Oral Surg Oral Med Oral Pathol Oral Radiol Endod 1998;85:325–328. Chadwick BL, Dummer PM, van der Stelt PF: The effect of alterations in horizontal X-ray beam angulation and bucco-lingual cavity width on the radiographic depth of approximal cavities. J Oral Rehabil 1999; 26: 292– 301. Clifton TL, Tyndall DA, Ludlow JB: Extraoral radiographic imaging of primary caries. Dentomaxillofac Radiol 1998;27:193–198. Costa AM, Yamaguti PM, De Paula LM, Bezerra AC: In vitro study of laser diode 655 nm diagnosis of occlusal caries. ASDC J Dent Child 2002;69:249–253, 233. Danforth RA: Cone beam volume tomography: a new digital imaging option for dentistry. J Calif Dent Assoc 2003;31:814–815. Farman AG: ALARA still applies. Oral Surg Oral Med Oral Pathol Oral Radiol Endod 2005; 100:395–397. Haiter-Neto F, Wenzel A, Gotfredsen E: Diagnostic accuracy of cone beam computed tomography scans compared with intraoral image modalities for detection of caries lesions. Dentomaxillofac Radiol 2008;37:18–22. Heinrich-Weltzien R, Kuhnisch J, Ifland S, Tranaeus S, Angmar-Mansson B, Stosser L: Detection of initial caries lesions on smooth surfaces by quantitative light-induced fluo-
Different Radiographic Methods for Detecting Caries
rescence and visual examination: an in vivo comparison. Eur J Oral Sci 2005;113:494–498. Hintze H, Frydenberg M, Wenzel A: Influence of number of surfaces and observers on statistical power in a multiobserver ROC radiographic caries detection study. Caries Res 2003;37:200–205. Hintze H, Wenzel A, Frydenberg M: Accuracy of caries detection with four storage phosphor systems and E-speed radiographs. Dentomaxillofac Radiol 2002;31:170–175. Jacobsen JH, Hansen B, Wenzel A, Hintze H: Relationship between histological and radiographic caries lesion depth measured in images from four digital radiography systems. Caries Res 2004;38:34–38. Kalathingal SM, Mol A, Tyndall DA, Caplan DJ: In vitro assessment of cone beam local computed tomography for proximal caries detection. Oral Surg Oral Med Oral Pathol Oral Radiol Endod 2007;104:699–704. Kamburoğlu K, Kurt H, Kolsuz E, Öztaş B, Tatar I, Çelik HH: Occlusal caries depth measurements obtained by five different imaging modalities. J Digit Imaging 2011; 24: 804– 813. Kamburoğlu K, Murat S, Yüksel SP, Cebeci AR, Paksoy CS: Occlusal caries detection by using a cone-beam CT with different voxel resolutions and a digital intraoral sensor. Oral Surg Oral Med Oral Pathol Oral Radiol Endod 2010;109:e63–e69. Kantor ML, Zeichner SJ, Valachovic RW, Reiskin AB: Efficacy of dental radiographic practices: options for image receptors, examination selection, and patient selection. J Am Dent Assoc 1989;119:259–268. Kayipmaz S, Sezgin OS, Saricaoglu ST, Can G: An in vitro comparison of diagnostic abilities of conventional radiography, storage phosphor, and cone beam computed tomography to determine occlusal and approximal caries. Eur J Radiol 2011;80:478–482. Ketley CE, Holt RD: Visual and radiographic diagnosis of occlusal caries in first permanent molars and in second primary molars. Br Dent J 1993;174:364–370. Kitagawa H, Scheetz JP, Farman AG: Comparison of complementary metal oxide semiconduc-
tor and charge-coupled device intraoral X-ray detectors using subjective image quality. Dentomaxillofac Radiol 2003;32:408–411. Kositbowornchai S, Basiw M, Promwang Y, Moragorn H, Sooksuntisakoonchai N: Accuracy of diagnosing occlusal caries using enhanced digital images. Dentomaxillofac Radiol 2004; 33:236–240. Ludlow JB, Davies-Ludlow LE, Brooks SL: Dosimetry of two extraoral direct digital imaging devices: NewTom cone beam CT and Orthophos Plus DS panoramic unit. Dentomaxillofac Radiol 2003;32:229–234. Naoum HJ, Chandler NP, Love RM: Conventional versus storage phosphor-plate digital images to visualize the root canal system contrasted with a radiopaque medium. J Endod 2003;29:349–352. Pai SS, Zimmerman JL: Digital radiographic imaging in dental practice. Dent Today 2002;21: 56–61. Parks ET, Williamson GF: Digital radiography: an overview. J Contemp Dent Pract 2002; 3: 23– 39. Paurazas SB, Geist JR, Pink FE, Hoen MM, Steiman HR: Comparison of diagnostic accuracy of digital imaging by using CCD and CMOSAPS sensors with E-speed film in the detection of periapical bony lesions. Oral Surg Oral Med Oral Pathol Oral Radiol Endod 2000;89: 356–362. Pontual AA, de Melo DP, de Almeida SM, Boscolo FN, Haiter Neto F: Comparison of digital systems and conventional dental film for the detection of approximal enamel caries. Dentomaxillofac Radiol 2010;39:431–436. Poorterman JH, Weerheijm KL, Groen HJ, Kalsbeek H: Clinical and radiographic judgement of occlusal caries in adolescents. Eur J Oral Sci 2000;108:93–98. Qu X, Li G, Zhang Z, Ma X: Detection accuracy of in vitro approximal caries by cone beam computed tomography images. Eur J Radiol 2011; 79:e24–e27. Rathore S, Tyndall D, Wright J, Everett E: Ex vivo comparison of Galileos cone beam CT and intraoral radiographs in detecting occlusal caries. Dentomaxillofac Radiol 2012; 41: 489– 493.
Caries Res 2014;48:566–574 DOI: 10.1159/000357596
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References
574
Tsuchida R, Araki K, Okano T: Evaluation of a limited cone-beam volumetric imaging system: comparison with film radiography in detecting incipient proximal caries. Oral Surg Oral Med Oral Pathol Oral Radiol Endod 2007;104:412–416. Tyndall DA, Rathore S: Cone-beam CT diagnostic applications: caries, periodontal bone assessment, and endodontic applications. Dent Clin North Am 2008;52:825–841. van der Stelt PF, Ruttiman UE, Webber RL, Heemstra P: In vitro study into the influence of X-ray beam angulation on the detection of artificial caries defects on bitewing radiographs. Caries Res 1989;23:334–341.
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Versteeg KH, Sanderink GC, Velders XL, van Ginkel FC, van der Stelt PF: In vivo study of approximal caries depth on storage phosphor plate images compared with dental X-ray film. Oral Surg Oral Med Oral Pathol Oral Radiol Endod 1997;84:210–213. Wenzel A: Current trends in radiographic caries imaging. Oral Surg Oral Med Oral Pathol Oral Radiol Endod 1995;80:527–539. Wenzel A: Digital imaging for dental caries. Dent Clin North Am 2000;44:319–338. Williams CP: Digital radiography sensors: CCD, CMOS, and PSP. Pract Proced Aesthet Dent 2001;13:395–396. Young SM, Lee JT, Hodges RJ, Chang TL, Elashoff DA, White SC: A comparative study of highresolution cone beam computed tomography and charge-coupled device sensors for detecting caries. Dentomaxillofac Radiol 2009; 38: 445–451. Ziegler CM, Woertche R, Brief J, Hassfeld S: Clinical indications for digital volume tomography in oral and maxillofacial surgery. Dentomaxillofac Radiol 2002;31:126–130.
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Reis A, Mendes FM, Angnes V, Angnes G, Grande RH, Loguercio AD: Performance of methods of occlusal caries detection in permanent teeth under clinical and laboratory conditions. J Dent 2006;34:89–96. Ricketts DN, Kidd EA, Smith BG, Wilson RF: Clinical and radiographic diagnosis of occlusal caries: a study in vitro. J Oral Rehabil 1995; 22:15–20. Scarfe WC, Farman AG: What is cone-beam CT and how does it work? Dent Clin North Am 2008;52:707–730. Sogur E, Baksı BG, Orhan K, Paksoy SC, Dogan S, Erdal YS, Mert A: Effect of tube potential and image receptor on the detection of natural proximal caries in primary teeth. Clin Oral Investig 2011;15:901–907. Souza-Zaroni WC, Ciccone JC, Souza-Gabriel AE, Ramos RP, Corona SA, Palma-Dibb RG: Validity and reproducibility of different combinations of methods for occlusal caries detection: an in vitro comparison. Caries Res 2006;40:194–201.
Caries Res 2014;48:566–574 DOI: 10.1159/000357596
A Comparative Study of Different Radiographic Methods for Detecting Occlusal Caries Lesions Elif Tarım Ertas a Ebru Küçükyılmaz b Hüseyin Ertaş c Selçuk Savaş b Meral Yırcalı Atıcı a
Departments of a Oral and Maxillofacial Radiology, b Pedodontics and c Endodontics, Faculty of Dentistry, Izmir Katip Çelebi University, Izmir, Turkey
Key Words Computed tomography · Dental caries · Diagnosis · Digital · Radiography
Abstract Objectives: The aim of this in vitro study was to compare the diagnostic accuracy of different radiographic imaging modalities in detecting occlusal caries lesions. Materials and Methods: Under standardized conditions, 125 extracted human permanent molar teeth with sound or occlusal caries lesions were radiographed using a conventional film system (F-speed), a direct digital imaging system (complementary metal oxide semiconductor sensor), an indirect digital imaging system (photostimulable phosphor plate) and a cone beam computed tomography system (CBCT). Two observers scored the resultant images for the presence or absence of caries. Then, the teeth were histologically prepared and a definite diagnosis was determined by stereomicroscopic assessment. The area under the receiver operating characteristic curve (Az), sensitivity, specificity and accuracy of each imaging modality were calculated, as well as the intra- and interexaminer reproducibility. Results: For both thresholds, interexaminer agreement were higher for CBCT. For intraexaminer agreement, observers had different scores for both thresholds, but the scores were generally higher for CBCT. Similar Az values were achieved with all imaging methods at
© 2014 S. Karger AG, Basel 0008–6568/14/0486–0566$39.50/0 E-Mail [email protected] www.karger.com/cre
a diagnostic D1 threshold. The Az values of the CBCT system were found to be statistically higher than those of the other imaging modalities at a diagnostic D3 threshold (p > 0.05); no significant differences were found among the other imaging modalities. All radiographic methods showed similar sensitivities, specificities and accuracy in detecting D1 threshold. The CBCT system showed higher sensitivity and accuracy in detecting dentine lesions. Conclusions: Within the limitations of this study, CBCT exhibited better performance in detecting deep occlusal caries lesions than the other radiographic systems. © 2014 S. Karger AG, Basel
In recent years, the prevalence of dental caries has declined worldwide in a remarkable way [Rathore et al., 2012]. However, accurately diagnosing occlusal pit and fissure caries and detecting incipient lesions are important issues for clinicians [Souza-Zaroni et al., 2006]. Using a visual/tactile method when diagnosing occlusal caries is the oldest and most common method preferred by dentists in clinical practice [Rathore et al., 2012]. Since occlusal caries can progress without visible breakdown of the enamel structure [Poorterman et al., 2000], visual examination alone is not always sufficient for diagnosing occlusal caries. In the literature, although visual inspection has been reported to be highly specific [Heinrich-Weltzien et Elif Tarım Ertaş, DDS, PhD Department of Oral and Maxillofacial Radiology Faculty of Dentistry, Izmir Katip Çelebi University TR–35180 Izmir (Turkey) E-Mail dteliftarim @ yahoo.com
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Different Radiographic Methods for Detecting Caries
[Kamburoğlu et al., 2011], at a lower cost and with lower absorbed doses than with the conventional computed tomography used in medical radiology [Tyndall and Rathore, 2008], a new technology that uses a 2D sensor and a cone-shaped beam in place of the fan-shaped X-ray beam used for conventional computed tomography has been developed [Haiter-Neto et al., 2008]. The development of cone beam computed tomography (CBCT) has been revolutionary in that this technology [Rathore et al., 2012] offers a number of potential advantages over conventional tomography, including easier image acquisition, higher image accuracy, fewer artifacts, lower effective radiation doses (up to 15 times lower than those of conventional computed tomography scans), faster scan times and greater cost effectiveness [Scarfe and Farman, 2008; Tyndall and Rathore, 2008]. This technique could be applied in several dental diagnostic areas, such as implant treatment, craniofacial anomalies, endodontic treatment, orthodontics, periodontology [Arai et al., 1999; Ziegler et al., 2002; Danforth, 2003] and caries diagnosis [Kayipmaz et al., 2011]. In the literature, the results of studies using CBCT for caries detection are not consistent with each other. In some studies, promising results have been reported in the detection of caries lesions [Haiter-Neto et al., 2008], while in another study, a limited CBCT system was found to be superior to conventional film and storage phosphor radiography for the in vitro assessment of approximate caries lesion depth [Akdeniz et al., 2006]. Tsuchida et al. [2007] and Haiter-Neto et al. [2008] had raters score images of teeth made with a CBCT unit and found no benefit over film for detecting incipient proximal surface caries [Young et al., 2009]. Thus, there are no clear conclusions regarding the value of CBCT for detecting caries in the literature. The purpose of the present study was to compare the caries diagnostic accuracy of conventional film radiography (Fspeed film), a direct digital imaging system (CMOS sensor), an indirect digital imaging system (PSP plate) and a CBCT unit that provides high-resolution images with the smallest voxel size (0.075 mm) on the market for the in vitro determination of occlusal caries.
Materials and Methods This study was approved by the Research Ethics Committee of Izmir Katip Çelebi University (registration number 2013-39). Sample Selection A total of 125 extracted permanent molar teeth exhibiting complete root formation were included in this study. Altered physical properties in the tooth structure, large cavitated surfaces and den-
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al., 2005; Reis et al., 2006], these methods are subjective, which normally leads to low sensitivity and reliability results [Ketley and Holt, 1993; Costa et al., 2002]. In order to overcome difficulties during diagnosis and enable better detection of occlusal caries, radiographic examinations, especially conventional film and digital intraoral radiography, are the most easily accessible techniques for improving caries detection in routine clinical practice [Kamburoğlu et al., 2010, 2011]. Recent developments in imaging systems and the production of new sensor types and advanced software programs offer increasing clinical advantages [Kayipmaz et al., 2011]. Although the image resolution of conventional film is superior to that of digital images [Parks and Williamson, 2002], this technique requires more radiation to produce an image of diagnostic quality; therefore, many professionals are now replacing conventional film radiographs with digital radiography, due to its many advantages [Cederberg et al., 1998; Paurazas et al., 2000; Williams, 2001; Kitagawa et al., 2003; Naoum et al., 2003; Kayipmaz et al., 2011]. There are several digital radiographic systems currently used in dental practice as an alternative to film-based radiography [Pontual et al., 2010]. The most common direct digital imaging systems use solid state sensors – either a charge-coupled device (CCD) or a complementary metal oxide semiconductor (CMOS); indirect digital imaging systems use photostimulable phosphor (PSP) plates, also known as storage phosphor plates [Kamburoğlu et al., 2010]. Although digital systems have a number of advantages [Wenzel, 1995; Hintze et al., 2002; Jacobsen et al., 2004], such as lower exposure dose, reduced working time from image exposure to image display (no wet processing is involved), lack of destroyed processing artifacts often experienced with conventional film, and possible image quality enhancements, such as contrast and density modulation, which might increase diagnostic accuracy [Wenzel, 1995, 2000; Hintze et al., 2002; Pai and Zimmerman, 2002], all of these systems are able to provide two-dimensional (2D) information about dental tissues and diseases [Wenzel, 2000]. Another disadvantage of 2D radiographs is that the apparent depth can also vary as a function of X-ray beam angulation [van der Stelt et al., 1989; Chadwick et al., 1999] and radiographic density [Versteeg et al., 1997], which can lead to variations in perception. The perceived lesion depth can lead dentists to erroneously believe that caries has progressed or regressed, resulting in unnecessary restorative intervention or delay in treatment [Akdeniz and Gröndahl, 2005]. Due to the high demand for a technique that can provide three-dimensional (3D) data at the tooth level
Conventional Film Radiography A bitewing technique using size 2 (3 × 4 mm) F-speed film (CFSPEEDX, Medex Medical Imaging, Nice, France) and standardized bitewing projection geometry was used. The intraoral X-ray unit (eXTtend; MyRay, Imola, Italy) was operated at 65 kV, 7 mA with 2.5 mm aluminium equivalent filtration. Focus-to-film distance was 30 cm. Each tooth was mounted in a block of silicone paste to ensure a reproducible geometry. While the vinyl polysiloxane putty was still soft, the film holder was pressed into it, and once hardened, the putty allowed quick realignment of the specimen as well as CMOS sensor, PSP plate and F-speed conventional films. A 20-mm-thick soft tissue equivalent Plexiglas block was placed close to the tooth and facing the X-ray tube to simulate scatter radiation and beam attenuation from soft tissues. The F-speed films were exposed for 0.25 s to generate an optimal density subjectively for caries detection [Sogur et al., 2011]. The exposed films were automatically processed (Velopex Extra-X; Medivance Instruments Ltd., London, UK) using fresh Kodak developer and fixer solutions. Direct Digital Radiography – CMOS Sensor Standardized images of the teeth were obtained using the same intraoral X-ray unit, but with a size 1 (37 × 24 mm) CMOS sensor (DIGORA Toto; SOREDEX, Milwaukee, Wisc., USA) with the same standardized projection geometry. The CMOS sensors were exposed for 0.12 s to generate an optimal density subjectively for caries detection [Sogur et al., 2011]. The direct digital imaging system provides three types of diagnostic modes (dentoenamel, periodontal and endodontic) at two levels (high and low) of spatial resolution. In this study, the exposures with the CMOS sensor were performed in the dentoenamel high-resolution mode, which was recommended by the manufacturer to provide high-contrast images for caries detection.
at a fixed 110 kVp setting, automated adjusted milliamperes and a scan time of 36 s. The volumetric data from the CBCT system were reconstructed and sectioned into 0.075-mm pieces in the mesiodistal tooth plane. Evaluation of Radiographic Methods The images were organized into groups of images from a particular exposure setting and system. Two observers (one pedodontist and one oral and maxillofacial radiologist) independently viewed the image groups in random order. The oral and maxillofacial radiologist with 10 years of experience in image interpretation provided a training session to familiarize the other observer with the presentation of all imaging methods and was given brief information about the use of the NNT viewing software (version 3.10, QR srl, Verona, Italy) on how to observe the CBCT images. Then the observers discussed and scored a number of teeth with carious lesions with different radiographic methods for calibration. The digital and CBCT images were displayed using the dedicated software of each imaging system incorporated into the same computer. Observation conditions were optimized by using the same computer monitor to display the images; the display ratio was 1:1. Viewing distance was kept constant, at about 50 cm, for all observers, and the lights were dimmed during the observations. The observers were not given the option of performing any image enhancements to avoid the production of a variety of different digital images. Conventional film radiographs were examined on a light box and at 2× magnification. A period of at least 1 day separated each viewing session. All tooth surfaces were examined for the presence of carious lesions on the occlusal surfaces, using a five-point confidence rating scale: 0 = no caries; 1 = radiolucency extending to the outer half of the enamel; 2 = radiolucency extending to the inner half of the enamel; 3 = radiolucency extending to the outer half of the dentine; 4 = radiolucency extending to the inner half of the dentine. Intraobserver agreement was assessed by having each observer view all images twice, with a 2-week interval between viewing to eliminate memory bias.
Indirect Digital Radiography – PSP Plate System Standardized images of the teeth were obtained using the same intraoral X-ray unit, but with size 2 (31 × 41 mm) VistaScan blue storage phosphor plates (Dürr Dental, Bietigheim-Bissingen, Germany) with the same standardized projection geometry. The PSP plates were exposed for 0.12 s to generate an optimal density subjectively for caries detection [Sogur et al., 2011]. The plates were later scanned in a VistaScan scanner. The PSP plates were stored in lightproof envelopes during the exposure and scanned immediately after exposure using the VistaScan scanner. The highresolution scan mode was selected from the scanner setup menu, as recommended by the manufacturer for most diagnostic tasks.
Histological Validation The teeth were individually embedded in acrylic (Vipcril; Vipi, São Paulo, Brazil) and serially sectioned into 700-μm-thick sections in the mesiodistal direction, using a water-cooled 200-μm diamond band. The histological examination was performed by one of the study authors (E.K.), with experience from several previous in vitro studies, using a stereomicroscope with a magnification of 10–20× under reflected light (Olympus SZ61, Tokyo, Japan). Caries was defined as being present when demineralization was observed, seen as a white or discolored (yellow/brown) area. The histological criteria for caries lesion depth were: 0 = no caries; 1 = demineralization extending to the outer half of the enamel; 2 = demineralization extending to the inner half of the enamel; 3 = demineralization extending to the outer half of the dentine; 4 = demineralization extending to the inner half of the dentine. As a measure of histological assessment reliability, all of the sections were re-examined after 10 days. Almost perfect agreement was reached between the first and second histological examinations.
CBCT Each tooth block was also radiographed using a NewTom 5G CBCT system (Verona, Italy) with a 6 × 6 cm field of view in the high-resolution denture scan mode. The voxel size was 0.075 mm3
Statistical Analysis The analyses of the caries detected on the radiographs were performed at two different thresholds: enamel and dentine caries lesions (D1 threshold; sound vs. decayed) and dentine caries le-
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tal restorations were not included in the study sample. The occlusal surfaces ranged from sound to varying degrees of fissure, discoloration and possible microscopic breakdown of the surface structure; however, none of the teeth showed macroscopic signs of cavity formation with exposure into the dentine. The teeth were stored in 0.1% thymol solution for less than 3 months from the time of extraction. For the study, the teeth were radiographed using four different radiographic methods.
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1.0
0.6
Results 0.4 Source of the curve Conventional film PSP CMOS CBCT Reference line
0.2
0 0
0.2
0.4 0.6 1 – Specificity
0.8
1.0
Fig. 1. Area under the ROC curve values of all radiographic detec-
tion methods at the D1 threshold. Diagonal segments are produced by ties.
Table 1. Sensitivity, specificity, accuracy and Az scores of all radio-
graphic detection methods at the D1 threshold Test method
Az
Sensitivity Specificity Accuracy
Conventional film PSP CMOS CBCT
0.851 0.824 0.834 0.801
0.798 0.713 0.830 0.926
0.903 0.935 0.839 0.677
0.824 0.768 0.832 0.864
sions (D3 threshold), based on the histological evaluation as the gold standard. The appropriate cutoff point for the D1 threshold was a score of 1 or above, considering the gold standard scores 1, 2 and 3 as evidence of disease for all radiographic methods. The appropriate cutoff point for the D3 threshold was a score of 3 or above, considering the gold standard scores 3 and above as evidence of disease for all radiographic methods. Data were presented and analyzed separately for each examiner. Inter- and intraexaminer reliabilities were calculated using Cohen’s kappa test after collapsing the results into two categories: D1 and D3 thresholds. For each observer and each radiographic modality, the sensitivity (cumulative percentage of carious enamel lesions identified among those that had carious lesions), specificity (cumulative percentage of sound surfaces identified among those who had sound surfaces) and accuracy (percentage of correct scores) were computed. To compare the performance of methods
Different Radiographic Methods for Detecting Caries
Distribution of Lesions A total of 125 occlusal surfaces were examined in the study. According to the histological examination, the status of the 125 occlusal surfaces was: 31 (24.8%) sound, 11 (8.8%) with caries lesions extending into the outer half of the enamel, 47 (37.6%) with caries lesions extending into the inner half of the enamel, 29 (23.2%) with caries lesions extending into the outer half of the dentine, and 7 (5.6%) with caries lesions extending into the inner half of the dentine. Occlusal Lesions at the D1 Threshold The sensitivity scores of the CBCT images of occlusal lesions at the D1 threshold were higher than those of the other imaging methods, while the specificity scores were lowest. However, the diagnostic accuracy of all radiographic systems was assessed using the Az, and similar accuracy scores were obtained with all imaging methods at the D1 threshold. A comparison of the Az values showed that the differences between the radiographic methods were not significant (p = 0.401 between conventional film and PSP plate, p = 0.725 between conventional film and CMOS sensor, p = 0.338 between conventional film and CBCT, p = 0.840 between PSP plate and CMOS sensor, p = 0.663 between PSP plate and CBCT, p = 0.447 between CMOS sensor and CBCT) (fig. 1). Table 1 shows the sensitivity, specificity, accuracy and Az values of all radiographic methods at the D1 threshold. Occlusal Lesions at the D3 Threshold The sensitivity scores of the CBCT images of occlusal lesions at the D3 threshold were higher than those of the other imaging methods. At the D3 threshold, similar specificity and accuracy scores were obtained with all imaging methods. A comparison of the Az values showed significant differences between CBCT and the other radiographic methods (p = 0.029 between conventional film and CBCT, p = 0.023 between PSP plate and CBCT, p = 0.014 between CMOS sensor and CBCT). There were Caries Res 2014;48:566–574 DOI: 10.1159/000357596
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Sensitivity
0.8
among each other, receiver operating characteristic (ROC) analyses were performed, and the area under the ROC curve (Az) at the D1 and D3 thresholds was calculated. Comparison of ROC curves was calculated with the statistics program MedCalc 9.3.0.0 (Mariakerke, Belgium). The analyses were performed using the SPSS statistics program for Windows, version 11.5 (SPSS Inc., Chicago, Ill., USA). For all statistical analyses, the level of significance was p < 0.05.
Color version available online
1.0
0.6
Az
Sensitivity Specificity Accuracy
Conventional film PSP CMOS CBCT
0.739a 0.730a 0.717a 0.875b
0.500 0.472 0.444 0.806
0.978 0.989 0.989 0.944
0.840 0.840 0.832 0.904
Different superscript letters show a significant difference between methods.
0.4 Source of the curve Conventional film PSP CMOS CBCT Reference line
0.2
0 0
0.2
0.4 0.6 1 – Specificity
0.8
1.0
Fig. 2. Area under the ROC curve values of all radiographic detec-
tion methods at the D3 threshold. Diagonal segments are produced by ties.
no differences among the other methods at the D3 threshold (p = 0.899 between conventional film and PSP plate, p = 0.732 between conventional film and CMOS sensor, p = 0.560 between PSP plate and CMOS sensor) (fig. 2). Table 2 shows the sensitivity, specificity, accuracy and Az values of all radiographic methods at the D3 threshold. In the kappa analysis of interexaminer agreement between the observers, conventional film radiography had the lowest scores at the D1 threshold, while the CBCT images had higher scores at both the D1 and D3 thresholds compared with the other methods. At the D3 threshold, repeatability between the observers was similar for all imaging methods and higher than the scores obtained at the D1 threshold (table 3). There was a high level of intraexaminer agreement between the two assessments of the observers for the CBCT images at the D3 threshold. The overall intraexaminer scores were compatible between the observers at both thresholds. Table 4 shows the intraexaminer agreement scores of both observers at both thresholds.
Discussion
The present research focused mainly on the diagnostic accuracy and reliability of observers regarding images obtained using different X-ray systems. This study found 570
Test method
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Table 3. Interexaminer kappa scores (with standard errors) of all radiographic detection methods at the D1 and D3 thresholds
Test method
D1
D3
Conventional film PSP CMOS CBCT
0.473 (0.071) 0.654 (0.068) 0.518 (0.083) 0.833 (0.061)
0.822 (0.070) 0.804 (0.071) 0.763 (0.079) 0.980 (0.020)
that intraoral analogue X-ray film, direct and indirect digital X-ray modalities (CMOS sensor and PSP plate) and CBCT performed similarly in detecting occlusal caries at the D1 threshold, and that CBCT performed better at the D3 threshold. In the present study, the occlusal surfaces ranged from sound to varying degrees of fissure, discoloration and possible microscopic breakdown of the surface structure; however, none of the teeth showed macroscopic signs of cavity formation with exposure into dentine, as we believe that if diagnostic differences between radiographic systems are to be found, their accuracy in detecting subtle pathological changes should be tested. An in vitro model was preferred in this radiological study, as ideal patient positioning is not always possible in an in vivo study and absolute reproducibility is limited. In addition, image quality may vary from one patient to another. Another advantage of this in vitro model is that the occlusal surfaces can be exposed to X-rays repeatedly and ideal positioning of the specimen with exact reproducibility is possible. However, the results of the present study might not correlate with clinical situations. This is because in clinical settings, movement of the patient decreases image resolution, restorations in the occlusal plane can cause metallic streaking artifacts in the occlusal plane, and the other head and neck structures can result Tarım Ertas/Küçükyılmaz/Ertaş/Savaş/ Yırcalı Atıcı
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Sensitivity
0.8
Table 2. Sensitivity, specificity, accuracy and Az scores of all radiographic detection methods at the D3 threshold
Table 4. Intraexaminer kappa scores (with standard errors) of all radiographic detection methods at the D1 and
D3 thresholds
Conventional film PSP CMOS CBCT
D1
D3
examiner 1
examiner 2
examiner 1
examiner 2
0.872 (0.044) 0.824 (0.051) 0.513 (0.077) 0.776 (0.067)
0.610 (0.073) 0.727 (0.059) 0.714 (0.064) 0.935 (0.037)
0.546 (0.111) 0.548 (0.106) 0.666 (0.093) 0.918 (0.040)
0.647 (0.100) 0.834 (0.072) 0.965 (0.035) 0.938 (0.035)
in scattering into the field of interest, thereby reducing contrast [Ricketts et al., 1995]. The accuracy of 2D systems is well established in the literature [Rathore et al., 2012]; however, the accuracy of both intraoral analogue X-ray film and digital X-ray sensor measurements is limited by the 2D nature of the technology. The lower radiation doses, superimposition of anatomical structures and patient-related factors that affect caries diagnosis are inevitable factors with 2D systems [Kamburoğlu et al., 2011]. In addition, the differences in mass between small, incipient lesions and the surrounding tissues are so small that they do not reflect density differences with 2D images [Akdeniz and Gröndahl, 2005]. In the past decade, the use of CBCT in dentistry has become more and more widespread, as the CBCT technology overcomes the irradiation geometry problems that can cause errors in caries diagnosis with 2D imaging [Akdeniz and Gröndahl, 2005]. In this study, the observers were calibrated for each radiographic interpretation, but some differences between the observers still occurred, which may be due to their levels of experience and training with these radiographic methods. In the present study, ROC analysis was used to evaluate the diagnostic performance of four radiographic methods. In this analysis, significant differences among the areas under the ROC curves of the competing techniques were compared [Kantor et al., 1989], and it was found that the area under the curve (AUC) reflected diagnostic performance more comprehensively than sensitivity and specificity did, which are considered only one cutoff point [Kositbowornchai et al., 2004]. The ROC curve distinguishes between the inherent capacities of the observers to under- and overread when interpreting imaging; therefore, this analysis provides the most meaningful approach to comparing the diagnostic performance of two or more different imaging modalities [Rathore et al., 2012]. In this analysis, an area of 1 represents
a perfect test, and anything near 0.5 is a poor test result [Hintze et al., 2003]. In the present study, the AUC values of the four radiographic methods were around 0.80–0.85 at the D1 threshold, indicating that none of the methods was superior to the others and that they performed well at the D1 threshold. In addition, the CBCT AUC values were higher than those of the other methods at the D3 threshold, and the scores were close to those of the other methods. In recent years, several studies have been carried out to evaluate the accuracy of CBCT in detecting caries lesions on proximal and occlusal surfaces, with varying results [Haiter-Neto et al., 2008; Young et al., 2009; Kamburoğlu et al., 2010; Qu et al., 2011]. In 2007, Kalathingal et al. published a study comparing a CBCT device (SIDEXIS sensor; Sirona Dental Systems, Bensheim, Germany) and conventional film radiography in the detection of proximal caries, and their results showed no differences between the two methods. In the same year, Tsuchida et al. reported that the accuracy of the 3D Accuitomo in evaluating incipient proximal caries was not superior to that of intraoral films. Similar to their previous finding, Haiter-Neto et al. [2008] reported no differences in specificity or overall true scores among the methods when comparing the diagnostic accuracy of two CBCT systems – NewTom 3G (Verona, Italy) and 3DX Accuitomo – with one digital PSP (DIGORA fmx) and one conventional film system (Kodak Insight) in detecting occlusal caries. Contrary to previous findings, Young et al. [2009] reported that Accuitomo 3DX images were superior to CCD projection images in detecting lesions extending into the dentine on occlusal and proximal surfaces. However, the authors concluded that the 3DX images did not offer significantly superior information for detecting proximal surface caries limited to the enamel compared with CCD projection imaging. The possible explanation for these differences in study results is that both Tsuchida
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[2008], who reported that the sensitivity of the two CBCT systems (Accuitomo and NewTom) was high, but that their specificity was low, resulting in an increase in falsepositive results. Similarly, in their study, Young et al. [2009] found more false-positive results in intact teeth, thus resulting in significantly lower average specificity scores for the 3DX images than for the CCD images. A possible explanation for this might be the beam-hardening artifacts that appear in the pericoronal area and may mislead observers in distinguishing pathologies with low density, such as caries lesions [Tsuchida et al., 2007]. In addition, sound dentine under some cusps may appear artifactually more radiolucent than the surrounding dentine on the CBCT images, and this difference between enamel and dentine density might lead observers to misinterpret these areas as dentinal occlusal caries, thereby elevating the sensitivity scores while depressing the specificity scores [Young et al., 2009; Kayipmaz et al., 2011]. It is possible that better training of observers regarding this misinterpretation might improve the observers’ specificity scores without significantly depressing their sensitivity scores [Young et al., 2009]. In clinical practice, when referring a patient for CBCT examination, one of the most important issues to keep in mind is the effective radiation dose. Although the effective dose is somewhat lower than that of medical computed tomography, the dose is relatively higher than in conventional imaging alternatives and intraoral examinations. It is critical that the potential patient benefits from a radiographic examination be balanced against the risk of exposure to ionizing radiation [Ludlow et al., 2003], and it is fundamental that diagnostic radiology and CBCT procedures should be reserved for selected cases [Farman, 2005]. It should also be noted that CBCT is not considered suitable for routine caries diagnosis, because the large majority of patients have metallic restorations that cause artifacts due to beam hardening and scatter that simulates recurrent caries, and because the quality of CBCT images can be seriously affected by patient motion [Clifton et al., 1998]. In conclusion, the NewTom 5G CBCT exhibited higher sensitivity for detecting occlusal lesions than the intraoral systems did, but the overall accuracy scores were similar at the D1 threshold. CBCT was more accurate in detecting lesions at the D3 threshold than the intraoral systems. However, it can be concluded that because of the possible disadvantages of CBCT systems in clinical practice, including relatively higher effective radiation doses as well as possible misdiagnosis due to the artifacts caused by movement and metallic artifacts, intraoral radiograTarım Ertas/Küçükyılmaz/Ertaş/Savaş/ Yırcalı Atıcı
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et al. [2007] and Haiter-Neto et al. [2008] used a population of teeth in which the vast majority of the proximal surface lesions were limited to the enamel, whereas Young et al. [2009] evaluated both enamel and dentinal lesions equally. The different distribution of lesion depths would make detecting lesions more challenging, especially when they are located in enamel. In a recent study by Rathore et al. [2012], no statistically significant differences were reported between the Sirona Galileos (Sirona Dental Systems) CBCT and conventional film radiography in detecting occlusal caries. The results of the present study are consistent with the data in the literature in that there were no differences between the four imaging methods in detecting occlusal caries at the D1 threshold (sound/decayed), whereas CBCT was superior in detecting dentine lesions. CBCT systems offer a feature whereby an area can be evaluated in three planes at the same time (axial, sagittal and coronal), and sections can be created with different slice thicknesses and intervals. In the present study, we chose the mesiodistal plane to validate occlusal surfaces, as in this section, occlusal surface demineralization can be evaluated clearly [Haiter-Neto et al., 2008]. However, it is critical that if the operator fails to choose the slice that shows the deepest extension of the lesion, he/she may misdiagnose the lesions [Akdeniz and Gröndahl, 2005]. It has been suggested that the small voxel sizes and thin slices are the potential advantages of a CBCT system in caries diagnosis [Kayipmaz et al., 2011]. The CBCT device used in the present study (NewTom 5G) offers the smallest voxel size (0.075 mm3) available on the market, and this is the first study in the literature to evaluate accuracy at the smallest voxel size. However, no statistically significant differences were found among the four radiographic methods in the diagnosis of occlusal caries lesions at the D1 threshold, even with the smallest voxel size. Consistent with this finding, in a recent study, Kamburoğlu et al. [2010] compared intraoral digital CCD sensor images and CBCT images obtained at different voxel resolutions in the in vitro detection of occlusal caries, and the authors concluded that there were no statistically significant differences between ultra-resolution images and high- and low-resolution images. In the present study, although the CBCT images had the highest sensitivity scores, the CBCT specificity scores were lowest at the D1 threshold, which means that CBCT performs better when detecting true carious lesions, but weakly when detecting real sound surfaces. The present finding is consistent with the result of Haiter-Neto et al.
phy methods are found to be sufficient and have practical, economical and low-dose features that are valuable for the routine assessment of caries.
the manuscript: E. Tarım Ertas. Critical revision of the manuscript for important intellectual content: H. Ertaş, E. Tarım Ertas. Approval of the version of the manuscript to be published: E. Tarım Ertas, H. Ertaş, E. Küçükyılmaz, S. Savaş, M. Yırcalı Atıcı.
Author Contributions Conception and design of study: E. Tarım Ertas. Acquisition of data: S. Savaş, M. Yırcalı Atıcı. Analysis and/or interpretation of data: E. Tarım Ertas, E. Küçükyılmaz, H. Ertaş. Drafting of
Disclosure Statement The authors declare that they have no conflicts of interest.
Akdeniz BG, Gröndahl HG: Proximal caries depth: agreement between limited cone-beam CT, storage phosphore and film radiography. Hacettepe Dishekimligi Fakultesi Dergisi 2005;29:7–12. Akdeniz BG, Gröndahl HG, Magnusson B: Accuracy of proximal caries depth measurements: comparison between limited cone beam computed tomography, storage phosphor and film radiography. Caries Res 2006; 40: 202– 207. Arai Y, Tammisalo E, Iwai K, Hashimoto K, Shinoda K: Development of a compact computed tomographic apparatus for dental use. Dentomaxillofac Radiol 1999;28:245–248. Cederberg RA, Tidwell E, Frederiksen NL, Benson BW: Endodontic working length assessment. Comparison of storage phosphor digital imaging and radiographic film. Oral Surg Oral Med Oral Pathol Oral Radiol Endod 1998;85:325–328. Chadwick BL, Dummer PM, van der Stelt PF: The effect of alterations in horizontal X-ray beam angulation and bucco-lingual cavity width on the radiographic depth of approximal cavities. J Oral Rehabil 1999; 26: 292– 301. Clifton TL, Tyndall DA, Ludlow JB: Extraoral radiographic imaging of primary caries. Dentomaxillofac Radiol 1998;27:193–198. Costa AM, Yamaguti PM, De Paula LM, Bezerra AC: In vitro study of laser diode 655 nm diagnosis of occlusal caries. ASDC J Dent Child 2002;69:249–253, 233. Danforth RA: Cone beam volume tomography: a new digital imaging option for dentistry. J Calif Dent Assoc 2003;31:814–815. Farman AG: ALARA still applies. Oral Surg Oral Med Oral Pathol Oral Radiol Endod 2005; 100:395–397. Haiter-Neto F, Wenzel A, Gotfredsen E: Diagnostic accuracy of cone beam computed tomography scans compared with intraoral image modalities for detection of caries lesions. Dentomaxillofac Radiol 2008;37:18–22. Heinrich-Weltzien R, Kuhnisch J, Ifland S, Tranaeus S, Angmar-Mansson B, Stosser L: Detection of initial caries lesions on smooth surfaces by quantitative light-induced fluo-
Different Radiographic Methods for Detecting Caries
rescence and visual examination: an in vivo comparison. Eur J Oral Sci 2005;113:494–498. Hintze H, Frydenberg M, Wenzel A: Influence of number of surfaces and observers on statistical power in a multiobserver ROC radiographic caries detection study. Caries Res 2003;37:200–205. Hintze H, Wenzel A, Frydenberg M: Accuracy of caries detection with four storage phosphor systems and E-speed radiographs. Dentomaxillofac Radiol 2002;31:170–175. Jacobsen JH, Hansen B, Wenzel A, Hintze H: Relationship between histological and radiographic caries lesion depth measured in images from four digital radiography systems. Caries Res 2004;38:34–38. Kalathingal SM, Mol A, Tyndall DA, Caplan DJ: In vitro assessment of cone beam local computed tomography for proximal caries detection. Oral Surg Oral Med Oral Pathol Oral Radiol Endod 2007;104:699–704. Kamburoğlu K, Kurt H, Kolsuz E, Öztaş B, Tatar I, Çelik HH: Occlusal caries depth measurements obtained by five different imaging modalities. J Digit Imaging 2011; 24: 804– 813. Kamburoğlu K, Murat S, Yüksel SP, Cebeci AR, Paksoy CS: Occlusal caries detection by using a cone-beam CT with different voxel resolutions and a digital intraoral sensor. Oral Surg Oral Med Oral Pathol Oral Radiol Endod 2010;109:e63–e69. Kantor ML, Zeichner SJ, Valachovic RW, Reiskin AB: Efficacy of dental radiographic practices: options for image receptors, examination selection, and patient selection. J Am Dent Assoc 1989;119:259–268. Kayipmaz S, Sezgin OS, Saricaoglu ST, Can G: An in vitro comparison of diagnostic abilities of conventional radiography, storage phosphor, and cone beam computed tomography to determine occlusal and approximal caries. Eur J Radiol 2011;80:478–482. Ketley CE, Holt RD: Visual and radiographic diagnosis of occlusal caries in first permanent molars and in second primary molars. Br Dent J 1993;174:364–370. Kitagawa H, Scheetz JP, Farman AG: Comparison of complementary metal oxide semiconduc-
tor and charge-coupled device intraoral X-ray detectors using subjective image quality. Dentomaxillofac Radiol 2003;32:408–411. Kositbowornchai S, Basiw M, Promwang Y, Moragorn H, Sooksuntisakoonchai N: Accuracy of diagnosing occlusal caries using enhanced digital images. Dentomaxillofac Radiol 2004; 33:236–240. Ludlow JB, Davies-Ludlow LE, Brooks SL: Dosimetry of two extraoral direct digital imaging devices: NewTom cone beam CT and Orthophos Plus DS panoramic unit. Dentomaxillofac Radiol 2003;32:229–234. Naoum HJ, Chandler NP, Love RM: Conventional versus storage phosphor-plate digital images to visualize the root canal system contrasted with a radiopaque medium. J Endod 2003;29:349–352. Pai SS, Zimmerman JL: Digital radiographic imaging in dental practice. Dent Today 2002;21: 56–61. Parks ET, Williamson GF: Digital radiography: an overview. J Contemp Dent Pract 2002; 3: 23– 39. Paurazas SB, Geist JR, Pink FE, Hoen MM, Steiman HR: Comparison of diagnostic accuracy of digital imaging by using CCD and CMOSAPS sensors with E-speed film in the detection of periapical bony lesions. Oral Surg Oral Med Oral Pathol Oral Radiol Endod 2000;89: 356–362. Pontual AA, de Melo DP, de Almeida SM, Boscolo FN, Haiter Neto F: Comparison of digital systems and conventional dental film for the detection of approximal enamel caries. Dentomaxillofac Radiol 2010;39:431–436. Poorterman JH, Weerheijm KL, Groen HJ, Kalsbeek H: Clinical and radiographic judgement of occlusal caries in adolescents. Eur J Oral Sci 2000;108:93–98. Qu X, Li G, Zhang Z, Ma X: Detection accuracy of in vitro approximal caries by cone beam computed tomography images. Eur J Radiol 2011; 79:e24–e27. Rathore S, Tyndall D, Wright J, Everett E: Ex vivo comparison of Galileos cone beam CT and intraoral radiographs in detecting occlusal caries. Dentomaxillofac Radiol 2012; 41: 489– 493.
Caries Res 2014;48:566–574 DOI: 10.1159/000357596
573
Downloaded by: UCSF Library & CKM 169.230.243.252 - 11/27/2014 3:27:14 PM
References
574
Tsuchida R, Araki K, Okano T: Evaluation of a limited cone-beam volumetric imaging system: comparison with film radiography in detecting incipient proximal caries. Oral Surg Oral Med Oral Pathol Oral Radiol Endod 2007;104:412–416. Tyndall DA, Rathore S: Cone-beam CT diagnostic applications: caries, periodontal bone assessment, and endodontic applications. Dent Clin North Am 2008;52:825–841. van der Stelt PF, Ruttiman UE, Webber RL, Heemstra P: In vitro study into the influence of X-ray beam angulation on the detection of artificial caries defects on bitewing radiographs. Caries Res 1989;23:334–341.
Caries Res 2014;48:566–574 DOI: 10.1159/000357596
Versteeg KH, Sanderink GC, Velders XL, van Ginkel FC, van der Stelt PF: In vivo study of approximal caries depth on storage phosphor plate images compared with dental X-ray film. Oral Surg Oral Med Oral Pathol Oral Radiol Endod 1997;84:210–213. Wenzel A: Current trends in radiographic caries imaging. Oral Surg Oral Med Oral Pathol Oral Radiol Endod 1995;80:527–539. Wenzel A: Digital imaging for dental caries. Dent Clin North Am 2000;44:319–338. Williams CP: Digital radiography sensors: CCD, CMOS, and PSP. Pract Proced Aesthet Dent 2001;13:395–396. Young SM, Lee JT, Hodges RJ, Chang TL, Elashoff DA, White SC: A comparative study of highresolution cone beam computed tomography and charge-coupled device sensors for detecting caries. Dentomaxillofac Radiol 2009; 38: 445–451. Ziegler CM, Woertche R, Brief J, Hassfeld S: Clinical indications for digital volume tomography in oral and maxillofacial surgery. Dentomaxillofac Radiol 2002;31:126–130.
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Reis A, Mendes FM, Angnes V, Angnes G, Grande RH, Loguercio AD: Performance of methods of occlusal caries detection in permanent teeth under clinical and laboratory conditions. J Dent 2006;34:89–96. Ricketts DN, Kidd EA, Smith BG, Wilson RF: Clinical and radiographic diagnosis of occlusal caries: a study in vitro. J Oral Rehabil 1995; 22:15–20. Scarfe WC, Farman AG: What is cone-beam CT and how does it work? Dent Clin North Am 2008;52:707–730. Sogur E, Baksı BG, Orhan K, Paksoy SC, Dogan S, Erdal YS, Mert A: Effect of tube potential and image receptor on the detection of natural proximal caries in primary teeth. Clin Oral Investig 2011;15:901–907. Souza-Zaroni WC, Ciccone JC, Souza-Gabriel AE, Ramos RP, Corona SA, Palma-Dibb RG: Validity and reproducibility of different combinations of methods for occlusal caries detection: an in vitro comparison. Caries Res 2006;40:194–201.
